Device for absorbing shocks



Jan. 3, 1928.

J. A. STEVENS DEVICE FOR ABSORBING SHOCKS Filed Oct. 5, 1925 qb illlllllll nl Patented Jan. 3, 1928.

36H31 STEVENS, OF LQVJ'ELL, MASSACHUSETTS, ASSIGNGR TO STEVENS PRODUCTSCMLANY, OF LOWELL, MASSACHUSETTS,

[L CGRPORATION OF DELAWARE.

DEVICE FOR ABSORBING SHOCKS.

Application filed October 3, 1925. Serial No. 60,294.

This invention relates to an improvement in shock absorbers for use inconjunction with the usual body springs of a vehicle. lhe tendency foran automobile, to assume a constant undulating movement when travel. ingat higher rates et speed is well appreciated and is due to the tactthat" even the best highways contain ripples that causo this undulating`n'iovei'nent and make it necessary ior an occupant ot a vehicle toexperience a rising' and falling' movement which is uupleasantandoftentimes a cause ot' illness. 1While lrnoivn shock absorbers haveeffectively solved the problem ot counteracting and neutralizingl shocksso that occupants of a vehicle receive shocks vvith greatly diminished'force and little or no discomfort the inability ot' shock absorbers toovercome and quickly damp the undulating tendency ot the springs andbody of the vehicle and return same to the normal positionot'equilibriul'n is a serious defect. ln tact, prior to this inventionshoch absorbers it suhiciently resilientand responsive to satisfactorilyabsoi-b shocks actually induced and accentuatezl the undulating'tendency ot the vehicle.

Objects ot this invention are to provide Y a shock al sorber that 'willreadily counteract the shocks received by the vehicle and react totransmit saine to the occupants thereof with little or no force and atthe saine time quicliy arrest the movement of the elements set in motionby reason of the shock so that continued relative movement between thesprings and body oft the vehicle is prevented; to arrange a rictionalresistance mechanism in a shock absorbing' device so that the normalposition ot the chassis or body et' the vehicle relative to the springsunder a normal load is effectively maintained; and to provide a deviceso simple in its construction that same can be easily applied to anautomobile or other vehicle Without changing' its parts.

Other objects of the invention Will be apparent from the detaileddescription and appended claims hereinafter set forth.. For purposes ofillustration the invention is shown in the accompanying' drawings., inwhich:

F 1 is a sideelevation et the shock absorbing; device showing sameconnected to the spring' and body ot' the vehicle;

Fig. 2 is a vertical sectional vieu' of the device on line 22 of Fig. 1;and

Fig. 3 frictional ot Fig. 2.

As illustrated, the numeral 1 designates the usual semi-elliptic spring'mounted on the arles oit a vehicle au d ad apted to support the usualchassis or trame 2. ln acordance with this invention a shock absorbingdevice designated as a u'hole by the numeral l is iuserted bet-Ween oneend of the leal spring 1 and the chassis or body 2. The shock absorber 3comprises a body portion 1 adapted to enclose a plunger rod 5 which isattached to a sleeve (i atits lower end. The sleeve t has on itsexterior surface spaced shoulders 7 and 8 forming seats l'or the coiledsprings 9 and 10 respectively. A Washer 11 Which is rigidly attached tothe upper end ot' the body portion 4 through the medium ot' screws orother suitable attachino means receives and centers the plunger rod 5relatively to the spherical casing or cylinder 153 which lorm acompression chamber 1% surrounding` the upper end of the body portion 1and enclosing said Washer 11. The lower end of the casing 13 is rigidlyattached to the upper peripheral end of the body portion #l through aseries ot screws 15. Enclosed Within the casing' 13 is an outer casis avertical sectional vieiv of the resistance mechanism on line 3 3 ing` offabric 16 containing an inner casina' 17 of rubber. The casing' 17 isadapted th be inflated through a valve 18 attached to the casino' andextending through the top ot the cylinder 13. The valve 1S may be ot thetype commonly employed for intlating pneumatic casings. The upper end ofthe plunger rod 5 .extends through an openingr in the Washer 11 into thecylinder member 13 and carries an adjustable piston head 19 having alocking nut 2O adapted to lock said piston head in adjusted position onsaid rod. A screiv 20 may be provided to fasten the rod 5 to the casing1G if desired. The head 19 bears against the lou'er side of the casing16, and further compresses the air in the compression chamber 11 on itsupward movement. An eye member 21 is suitably mountedon the end ot thetrame or chassis 2 of the vehicle and is pivotally attached to a spindle22 mounted on the inner end ot an arm 23 extending from the body portion4l. The arm 23 at its upper end carries a bolt 24: receiving' the end ota projection 25 rigidly mounted on the chassis or body 2. An arm 26 ispivotally mounted interdas mediate its end by a pin 26 extending throughthe pivot on the lower end of the sleeve 6. @ne end of the arm 26 isattached to a spindle 27 pivoted in the main body 4 of the device whilethe opposite end of said arm pivotally receives the eye 28 of the leafspring 1 permitting free movement between said leaf spring and the shockabsorbing element. The parts .above described function to effectivelycounteractand neutralize the shocks received by the vehicle so thatvshocks are very lightly transmitted to the occupantsthereof. Howeverthe aforesaid. parts alone do not overcome the tendency of the chassisor frame of the vehicle to assume an undulating movement. In 'fact thepneumatic.cushion and auxiliary springs, as has been previouslysuggested, tend to increase the undulations of the vehicle and for thatreason the frictional resistance mechanism hereinafter describedpeculiarly coope'ates with the shock absorber previously described toproduce a structure in its entirety which has all of the benefits of thepneumatic shock absorber and overcomes all of its defects. rThe spindle27 has a squared extremity 29 cooperating with the frictional resistancemechanism in a manner hereinafter described. Y

The fri'ctional resistance mechanism designated as a whole by thenumeral 30 comrises a casing 31 suitably fastened to the idody of theshock absorber through the medium of bolts Casing 3l is provided with aninternal recess 33 receiving a cylindrical sleeve 34, fitting thelinterior walls of the casing but terminating short of the end thereof.rlhe walls of the casing 31 are provided with annular grooves orchannels 35 and 36 (Fig. 3)- which open into a. fluid storage cavity 37,said cavity being-provider with a filling opening adapted to be closedby the plug 33. The recess 33, the channels and 36 and the fluid storagecavity 37 are filled with oil or any other suitable fluid. A shaft 39having cavities 40 and 41 respectively, at each end is adapted toslidably embrace a bearing pin 42 integral with theV rear wall of thecasing 3l at one end while v its other end receivesv the spindle 27,said cavity receiving the spindle 27 being angular to correspond to theangular extremity 29 of said spindle, so that it is rotatable therewithbut adapted to be slidable relatively thereto. A coil spring 43 islocated within the cavity and bears against the pin 42 and wall of saidcavity and tends to force the shaft 39 to the right in Fig. 2. A lpiston44 accurately fitted'within sleeve 34 and integral with the shaft 39 isprovided with cam'v surfaces cooperating with corresponding cam surfaceson the interior of the cover 45, said cover 45 being attached to thecasing 3l through the medium of the bolts 46. The cover 45 is providedwithV a stuffing box-46 and cover 47 for holding a packing 48aroundshaft 39 whereby leakage of fluid around said shaft is prevented. Y v

The piston 44 is provided with a series of annular ports 49 throughYwhich the fluid contained in tue cylinder 33 is enabled to pass whendisplaced by said piston. `An annular valve50 is maintained in contactwith the ports 49 on one side of the piston by a coil spring'l placedbetween said valve and the wall of' casing 3l whereby the ports areclosed when the piston 44 moves to the left in Fig. 2 and open to allowa flow of fluid theretl'irough when the piston is moved in an oppositedirection. An opening 52 in sleeve'fi (Fig. 3) constitutes the onlymeans of egress for the fluid confined in the cylinder 33 at the left ofthe piston in Fig. 2. The opening 52 connects witha passage 53 below avalve seat 54 formed in the casing 2 as shown in Fig. 3. A compressioncoil spring mounted in a cavity formed in lug 53 of casing 3l serves tohold a valve 57 normally in contact with the valve seat 54. A valve stem53 extends into a recess 59 in the closure plug G0 fitted to the lug'56,the bottoinof' said recess engaging the end of said valve stem andthus-limiting the movenient of the valve 57. The interior of lug 56 isin communication with the annular groove 35 so that any fluid passingthrough the opening 52 and passage 53 will7 if under sullicient pressureraise valve 57 and pass through annular groove 35 to the portion of therecess 33 betweenthe piston 44 and cover 45. The bearing pin 42 isprovided with a groove Gl to allow the fluid to pass readily in and outof the cavity 40 containing the spring 43. l I Y rlChe operation of thedevice is as follows: when the vehicle von which the device is mountedsustains a shock it is transniitteil to the leaf spring l and plungerrod 5 attached thereto through the arm 262s() that said rod will Amoveupwardly withinthe compression chamber i3 with the result that thechassis 2 and leaf spring l tend to vapproach each other. On thereact-ing movement of the plunger' rod 5 the chassis 2 and the leafspring l will tend to separate. Anv movement of the leaf spring l willnecessarily impart a movement to the plunger rofl 5 and the arm 2G whichis mounted on both the leaf spring and the plunger rod. lnasmuch as arm26 is also attached by pin 26 to the spindle 27 movement of said armwill cause rotation of the spindle and consequently of the shaft 39rotatable withsaid spindle. The shaft 39, however, is hindered in itsmovement by reason of the frictional resistance mechanism whose opera-`tion is as follows: assuming that the spring l and arm 26 are movingupwardly in response to a .shock the spindle 27 is caused lua iso

to iotate in a clockwise direction as viewed in Fig. l transmitting asimilarrotational movement to the shaft 39. rlhis clockwise movement otthe shaft 39 causes the shaft to nieve to the lett compressing thesiring as viewed in Fig. 2 by reason ot the tact that the cam surfaceson the piston lll coact with the ycam surfaces on the stationary cover-l whereby said piston and shaft are moved to the lett from anintermediate position. The movement of the piston let to the lett exertsa pressure on the spring 5l sutiicient to retain the valve 5() in aclosed position and causes the fluid contained in the space 33 at thelett of the piston to be placed under compression Wnereby the fluid is`lorced through the opening o2 and passage 53 causing the alve 57 toopen ag inst the tension et the spring 55 and permitting the fluid toreturn to the grooves or channels 35 and 36 and the portion of the spaceat the right oi tie piston all. On the reacting or downward movement ofthe piston 5 the spindle 2T and shaft 3,9 vvill be rotated in acountei'clocliivise direction s that the piston Llll and shaft 39 vvilltend to move to the right as viewed in Fig. 2. This reacting` movementpermits the valve to open When the pressure ot the fluid in the space 33at the right or" the piston is .sutilcient to overcome the tension or'the spring 5l so that a portion ot said fluid is torced through theports i9 into the space 33 at the lett ot the piston Ul and the lirstdescribed ope ation ot the frietional resistance mechanism is ready tobegin. As vievved in F ig. 2 the position of the shaft 259 on thespindle 27 and piston la relative to the cover l5 represents the normalintermediate position of the various movable elements under ordinaryload. Any mov-ment ot the sha'lit 39 to the left or right of theposition shown in Fig. 2 will obviously be opposed by an increasingretarding torce on the part oi the trictional resistance mechanismWiereby said mechanism not only .serves to cooperate with the otherelements et' the sh cli absorber to soilten and neutralize shocls but isadapted to exercise an increasing resisting force on relative movementbetween the spring l and chassis 2. rllhe maximum retarding influenceot' the iii'ctional re nance mechanism is exercised on the upsti'ole ofthe piston due to the i'csistanre ot the mechanism ot valve lt theripples on the highway tend to sustain the movable elements of the shockabsorbing device 3 in their movement after being set' in motion by ashock the trictional resistance mechanism 30 will serve to quickly dampthis movement and equilibrize the forces acting on the shock absorbingelement. rlhe friction clutch mechanism 80, therefore, not only serv tocheck the rapid Oscillating tendency Which normally rounding lello-Ws ashock but also overcomes the undulating movement ol the vehicle byreason or" the intensified force ot its on the device 3 vvhich graduallyincreases in intensity when the springs ano. chasis et the vehicle moverelative to one another in response to a` shoch. The application ot "liedevice here .shown and described is not restricted toa itomobiles orother vehicles but "lie device may be used wherever there are twomovable relatively to each other by a sudden movement vvhich it is.desired to cushion. l do not ivish therefore to be limited to thespecitic torni ot the device here shown or to the specii'ic applicationot it to an automobile but merely by the sco pe oi" the appended claims.

l claim:

l. A shock absorber adapted to be mounted on a vehicle con'ipi'isiiigmeans for neutralizing and eounteraeting the shocks received by saidvehicle, said means comprising a piston operable to compress air in acollapsible vessel and simultaneously to compress tvvo or more springs,and a lirictional resistaA ce mechanism tor quickly arresting therelative movement of the parte ot the shock absorber to bring them to astate oi"A equilibrium. i'

A shock absorber adapted to be mountedon a vehicle comprising'pneumaticmeans for neutrali/:ing and counteracting the shoclis received by saidvehicle, and a kclutch mechanism tei' quickly arresting relativemovement ot the parts of the shock absorber to bring them to a state oiequilibrium.

A shock absorber adapted to be mounted betvveen the trame and springs ofthe vehicle comprising a compression chamber containing compressed air,a plunger adapted to oscillate in said chamber, and means acting inparallel with the plunger and compression chamber as a drag on theplunger vand exercising its maximum Vretarding inlinence on theupstrolre thereof quickly to arrest the relative movement of said'plunger and chamber.

4f. A shock absorber adapte'l to be mountpriiigs olf the compressionchamber air, a plunger adaptto oscillate in said chamber, and meansattached to said plunger acting in parallel therewith as a drag thereonand exercising maximum retarding influence on the upstrolre of saidplunger quickly to arrest the .relative movement of said plunge' andchamber.

l sh ci; absorber for vehicles comprising` a. compression chambercontaining vessel Vfilled with compressible liuid. a plunger rod havinga head adapted to oscillate in said chamber and bear on the ivalls ofsaid v .ss-el. a coiled spring surl' he plunger rod and adapted to edbetween the trame and vehicle comprising a containing compresser`pre-ssible fluid, a piston therein,

be compressed on the upward movement thereof, and means acting as .adrag on said head and exercising its inaxiii'iuin retarding effect onthe upstrolie thereof quickly to arrest the relative n'ioveiiient otsaid head in said chamber.

6. A. sliccl; absorber for a vehicle coinprising a. compression chamber,a plunger rod having a head adapted to oscillate in said chamber, arelatively. large coiled springl surrounding the plunger rod and adaptedto be compressed on the upward movement thereol, a relatively smallcoiled spring surrounding the plunger and contained within the largecoiled spring. and means acting as a diag on said l'iead and exercisingits inai-iiinuin ret-aiding elicct on theA upstrolve' tlicreot' quicklyto arrest the relative ii'iovcnicnt ot said head in ,said cli amber. c

7. A shock absorber' adapted to be mounted between the frame and.springs of a. vehicle comprisingl a compression chambercontainingcompressed ci# a. plunger adapted to oscillate in saidchamber, an arni attached to said plunger and movable tlierewith, aspindle attached to said arm and rotatable inv response to aii'iovenienl; tliereol. a. cam nieiiiber engaging said spindle androtatabletherewith, adapted to 'frictioiiallv engage a conipleineutalcani ineinbcr on movementv of said spindle.

S. A shock absorber for a vehicle corn )risino' acomiressionelian'ilzer. a plunger P1 i ti rod having a head adapted to oscillateinsaid chamber, a relatively large coiled spring surrounding `the plungerrod and adapted to be coii'ipressed on the upward nioven'ient ot thehead, a relatively small coiledspring` siii-rounding the plunger andcontained within the large coiled spring, a spindle carryingcomplemental engaging cam ineinbeis rotatable in response to themovement of ysaid plunger and adapted to act as a drag on the upstrokethereot quicklyv to arrest tlie relative movement o'tsaid head in saidchamber.

i). A sliocl: absorberadapted to be mounteilou a vehicle comprisingpneumatic ii'ieans 'for nsutralizingl and couiiteracting the fflieclzsreceived by said vehicle and fluid displacement means for quicklyarresting relative iiioveineiit ot the parts ol the shock absorber tobring tlieiii into a state oi" equi` libriuiii, said last'iiientioiiivlmeans being operable by a clutch mechanism which is actuated by arelative movement ot thc vehicle and the springs thereof.

l0. A shock absorber for a vehicle coiiiprising means for neutralizingand counteracting the'slioclrs received by said vehicle, and dampcningmeans quickly to arrest tli/e oscillations of thelirst mentioned meanscomprising a cylinder filled with a non-coin- Y the piston Lessinesbeing given a rotary movement by relative movement of the body andsprings of the, vehicle, the rotary movement causing longitudinalmovement by the action` of a cam.

1l. A shock absorber fora vehicle coinprising means for neutralizing andcounteracting the shocks received by said vehicle, and dampening meansquickly to arrest the oscillations of the first mentioned meanscomprising a.A cylinder filled Wtih a nonconipressible fluid, a camoperated piston therein, a bleed opening in the piston head and achecl;valve cont-rolling` said bleed opening and allowing flow in only onedirection therethrough.

l2. A shockv absorber for va vehicle coniprisiiig means forneutralizing` and counteracting the shocks received by said vehicle, anddanipeiiing inea quickly to arrest the oscillations ot the firstmentioned means comprising a cylinder filled ivith a non-coinprea-si'blefluid, a cani operated piston therein, al bleed opening in the lpistonhead, a check valve controlling said bleed opening, and allowing vflou'inY only one direction therethrough, and a` by-pass around said pistoncontrolled by a spring'lnfessed valve, whereby the pressure of the:fluid passing through the valve `is controlled by thetcnsion of thespring.

13. A shocl; absorber for a vehicle coinprising means l'or neutralizingand counteracting the shocks received by said vehicle, and dampeningmeans quickly to arrest the oscillations ot' the first mentioned meanscomprising a cylinder filled with a non-coni- )ressible fluid, a pistontherein, the piston being given a rotary movement by relative movementof the body and .springs of the vehicle, the rotary movement causinglongitudinal movement by the actions of a cam, a bleed opening inthepiston head, a check valve controlling the bleed opening and allowingflow ot fluid in only one direction therethrough, and ra-ivalvecontrolled bypass around said piston providing the sole path for flowot' fluid in tlie direction opposite to thecfloiv past said check valve.

lll. A shock absorber tor a vehicle coniprising means for neutralizingand counteracting the shocks received by said vehicle, and dainpeningmeans quickly to arrest the oscillations of the first mentioned meanscomprising a cylinder lled withia non-coinpi'essible fluid, a pistontherein, and at least tivo one-Way valves controlling the passage offluid from one side of the piston to the other, one operating in eitherdirection.

15. A shock absorber for a vehicle comprising means for neutralizing andcounteractiiig the shocks received by said vehicle, and dampeningmeansquickly to arrest the oscillations of the first mentioned meanscomprising a cylinder filled with a non-conipressible fluid, a pistontherein, at least tivo Y llfi ilo

lili) ono-Way valves controlling the passage of fluid from one side otthe piston to the other, one operating in either direction, and springsholding said one-Way valves in place Whereby the pressure of iiuidrequired to cause a flow through the valves is dependent on the tensionof said springs.

16. An apparatus 'for absorbing` the shocks caused by the relativemovement et tivo members comprising means tor neutralizing andcounteraeting the shocks caused by the relative movement ot saidmembers, and a clutch mechanism tor quickly arresting relative .movementot the parts of the shock absorbing mechanism to bring them to a stateot equilibrium.

17. An apparatus for absorbing the shocks caused by the relativemovement ot tivo members comprising a compression chamber adapted to befixed to one of said members, a plunger rod carried by the other of saidmembers and having a head adapted to osoillate in said chamber, arelatively large coiled spring surrounding` the plunger rod and adaptedto be compressed on the upward movement thereof, a relatively smallcoiled spring` surrounding the plunoer and contained Within the largecoiled spring, and means acting as a drag on said head and e);-erc-ising its maximum retarding eiecton the upstrolre thereof to quicklyarrest the relative movement ot said head in said chamber.

18. An apparatus for absorbing the shocks caused by the relativomovement of two members comprising a compression chamber containing acompressible fluid, said chamber adapted to be fixed to one oit' saidmembers, a plunger adapted to be carried by the other ot said membersand to oscillate in said chamber, an arm attached to said plunger andmovable therewith, a spindle attached to said arm and rotatable inresponse to a movement thereof, a cam member engaging said spindle. androtatable therewith, adapted to iiictionally engage a complemental cammember on movement el said spindle.

19. An apparatus :tor absorbing` the shocks caused by the relativemovement of tivo members comprising :i compression chamber adapted to befixed to one oi said members, a plunger rod adapted to be carried by theother of .said members having a head adapted to oscillate in saidchamber, a relatively large coiled spring surrounding the plunger rodand adapted to be compressed on the up- 'ward movement oit the head, arelatively small coiled spring' surrounding the plunger and containedWithin the large coiled spring, a spindle carrying` complementalengaging cam members rotatable in response to the movement ot saidplunger and adapted to act as a drag` on the upstrolre thereof quicklyto arrest the relative movement of said head in said chamber.

Signed by me at Lowell, Massachusetts, this 28th day of September, 1925.

JGHN A. STEVENS.

